The present invention relates to an operation board--remote I/O communication controlling system, and in particular to an operation board--remote I/O communication controlling system having an operation board that communicates with a controlling unit such as an NC (numerical controller) unit, a PC (programmable controller) unit, or the like, and a remote I/O that communicates with the controlling unit and that has an I/O portion for a machine connected to the controlling unit. In addition, the present invention is directed to an operation board--remote I/O communication controlling system with improved flexibility of connections between the controlling unit and the operation board and between the controlling unit and the remote I/O.
FIG. 16 is a block diagram showing a structure of a conventional operation board--remote I/O communication controlling system. FIG. 16 shows the structure of connections of an NC unit as a controlling unit, remote I/Os, an operation board, and servo amplifiers/spindle amplifiers.
MPU 101 controls the entire NC unit 1, using an operation program stored in ROM 102. RAM 103 is used as an operation work area for MPU 101. The communication controlling portion 104 is disposed in the NC unit 1 and communicates between the NC unit 1 and the operation board 3. The communication controlling portion 105 communicates between the NC unit 1 and the remote I/Os 2. The communication controlling portion 106 communicates between the NC unit 1 and the servo amplifiers/spindle amplifiers 4.
Operation boards 3 include operation key switches 107 and a display portion 108. Transmit/receive signal line 111 is connected between the NC unit 1 and the remote I/Os 2, transmit/receive signal line 112 is connected between the operation board 3 and the NC unit 1, and transmit/receive signal line 113 is connected between the servo amplifiers/spindle amplifiers 4 and the NC unit 1.
FIG. 17 shows an outlined structure of the conventional operation board 3. MPU 21 controls the entire operation board 3. The communication controlling portion 22 communicates with the NC unit 1. ROM 23 stores program software for controlling the operation of the MPU 21. RAM 24 is used as an operation work area of the MPU 21 of the operation board 3. The LED output storing portion 25 is used to output data to the LED display devices 108 of the operation board 3. The scan address generating portion 26 generates an address at which an operation key of the operation board 3 is scanned. The scan data input portion 27 inputs data of an operation key scanned corresponding to an address generated by the scan address generating portion 26. Reference numeral 28 is a switch/LED matrix on the operation board operated by the operator. Reference numeral 29 is an operation board selecting switch for selecting the type of the operation board 3.
FIG. 18 shows an outlined structure of the conventional remote I/O. Transmitting portion 31 transmits data from the remote I/O 2 to the NC unit 1. Receiving portion 32 receives data transmitted from the NC unit 1 to the remote I/O 2. Transmit data storing portion 33 stores data transmitted from the transmitting portion 31. Receive data storing portion 34 stores data received by the receiving portion 32. Filter portion 35 filters a remote I/O input signal that is input to the remote I/O 2. Remote I/O output signal storing portion 36 stores a remote I/O output signal that is input from the receive data storing portion 34. Receive alarm detecting portion 37 receives a receive state signal from the receiving portion 32 and outputs a reset signal to the output signal storing portion 36 when a non-receive state continues for a predetermined time period. Remote I/O station number designating rotary switch 38 designates a station number of the remote I/O 2. In the structure of the remote I/O 2 shown in FIG. 2, input/output signals are input and output to/from the remote I/O 2 and data is transmitted and received to/from the NC unit 1. The remote I/O 2 is composed of the communication controlling portion.
FIG. 19 is a block diagram showing an outlined structure of a communication controlling portion 104 for the operation board. The communication controlling portion 104 is disposed in the conventional NC unit 1.
As shown in FIG. 19, transmitting portion 41 transmits data from the NC unit 1 to the operation board 3. Receiving portion 42 receives data transmitted from the operation board 3 to the NC unit 1. Transmit data storing portion 43 stores data transmitted from the transmitting portion 41 to the operation board 3. Receive data storing portion 44 stores data received from the operation board 3. Transmit start command controlling portion 45 outputs a transmit start command with which the MPU 101 of the NC unit 1 causes the transmitting portion 41 to transmit data. Transmit status controlling portion 46 is used by the MPU 101 of the NC unit 1 to monitor the transmit status of the transmitting portion 41. Receive start command controlling portion 47 outputs a receive start command with which the MPU 101 causes the receiving portion to receive data. Receive status controlling portion 48 is used by the MPU 101 to monitor the receive status.
As shown in FIGS. 16 to 19, data transmission/reception between the NC unit 1 and the operation board 3 and data transmission/reception between the NC unit 1 and the remote I/O 2 are independently performed. The NC unit 1 and the remote I/O 2 are serially connected. In addition, as with the NC unit 1, the operation board 3 is controlled by the MPU 21 of the operation board 3 corresponding to software. Software processes of the MPU 21 of the operation board 3 include a process for transmitting input data of the operation keys 107 performed by the operator to the NC unit 1 and a process for outputting data transmitted from the NC unit 1 to the LED display devices 108 so as to inform the operator of the status of the NC unit 1.
As shown in FIG. 18, the remote I/O 2 is composed of the communication controlling portion. Unlike with the NC unit 1 and the operation board 3, the operation of the remote I/O 2 is not controlled by an MPU.
Next, the operation of the operation board in the conventional operation board--remote I/O communication controlling system shown in FIGS. 16 to 19 will be described. The remote I/O does not have an MPU. The operation of the remote I/O is not controlled by the MPU. Thus, the remote I/O is operated as the communication controlling portion. The remote I/O is controlled by the NC unit 1.
FIG. 20 shows an operational flow of a program software process of the MPU 101 of the conventional NC unit 1. FIG. 21 shows an operational flow of a program software process of the MPU 101 of the conventional NC unit 1 for inputs/outputs with the operation board 3 and the remote I/O 2. FIG. 22 shows an operational flow of a program software process of a controlling MPU 21 of the operation board 3.
Generally, a machine tool that uses an NC unit is equipped with an operation board corresponding to features of the machine tool. Thus, there are many types of operation boards. When the system of the NC unit is started, the operation board used for the machine tool has not been detected.
Thus, as shown in FIG. 20, when the system of the NC unit 1 is started, the MPU 101 of the NC unit 1 generates a frame with which the NC unit 1 requests the status of the operation board 3 (at step S1). In other words, the MPU 101 generates a frame for detecting what type of an operation board has been connected to the NC unit 1. At step S2, the MPU 101 of the NC unit 1 transmits the generated frame to the operation board 3. The operation board 3 receives the frame and transmits a frame containing status information corresponding to the received frame to the NC unit 1. The NC unit 1 receives the frame at step S3. The NC unit 1 analyzes the received status information (at step S4). The NC unit 1 executes an operation key input process for the operation board 3 corresponding to the analyzed result and a data output process for data to LED display devices 108 of the operation board 3 (at step S5).
After the NC unit 1 has analyzed the status for the type of the operation board 3, the mode of the MPU 101 of the NC unit 1 is changed from the status request mode to the normal mode. The operation board 3 generates and transmits a normal transmit frame to the LED display devices 108 (at step S6). In addition, the operation board 3 receives a frame containing input data of the operation keys 107 from the operation board 3 (at step S7). Whenever the MPU 101 of the NC unit 1 receives a frame, it analyzes the receive status and the receive data. In addition, the MPU 101 generates and transmits a normal transmit frame containing data that is output to the LED display devices 108 of the operation board 3 (at step S8). The operation mode of the NC unit 1 is changed corresponding to the input data of the operation keys 107 of the operation board 3. The NC unit 1 transmits data to the LED display devices 108 corresponding to the operation mode.
FIG. 21 shows an operational flow of a program software process of the MPU 101 of the NC unit 1 for inputs/outputs with the operation board 3 and the remote I/O 2. The NC unit 1 cyclically communicates with the operation board 3 and the remote I/O 2.
In other words, corresponding to a cyclic timer interrupt, the NC unit 1 performs the input/output process for the operation board 3 corresponding to the flow shown in FIG. 20 (at step S61). Thereafter, the NC unit 1 performs the normal input/output process for the remote I/O (at step S62). After that, the NC unit 1 performs another process (at step S63). Thereafter, the NC unit 1 returns from the interrupt process routine.
Next, with reference to a program software process flow of the MPU 21 of the operation board 3 shown in FIG. 22, the operation of the MPU 21 will be described.
When the system is started, the MPU 21 initializes the inside thereof and the input/output ports 25 and 27, and the communication controlling portion 22 reads switch information from the operation keys 107 of the operation board 3, and enters a receive waiting state in which the MPU 21 waits for a frame from the NC unit 1 (at step S2 1). When the MPU 21 detects that a frame has been received from the NC unit 1 (at step S22), the MPU 21 determines whether or not the frame has been correctly received (at step S23). When the frame has been correctly received, the MPU 21 stores display output data for the LED display devices 108 to the output storing portion 25 and sets a normal receive status to the frame to be transmitted to the NC unit 1 (at step S24). When the MPU 21 detects a receive error, it sets a receive error status to a frame to be transmitted to the NC unit 1 (at step S25).
Next, the MPU 21 determines whether or not the frame received from the NC unit 1 represents a connection ID request communication mode in which the NC unit 1 requests the MPU 21 to reply with the type of the connected operation board or a normal transmit mode (at step S26). When the frame represents the connection ID request communication mode, the MPU 21 generates the connection ID transmit frame that contains the status information (at step S27), transmits the frame to the NC unit 1 (at step S28), and enters the receive waiting state (at step S22).
When the frame transmitted from the NC unit 1 is a normal transmit frame, the MPU 21 stores the display output data for the LED display devices 108 to the LED output storing portion 25 of the operation board 3 (at step S29), generates the normal transmit frame for the NC unit 1 corresponding to the input data of the operation keys 107 of the operation board 3 (at step S30), transmits the normal transmit frame to the NC unit 1 (at step S31), and enters the data receive waiting state (at step S22).
In other words, when the operation board 3 detects a frame that has been transmitted from the NC unit 1 to the operation board 3, the MPU 21 determines whether or not the frame is a connection ID request communication frame or a normal transmit frame. This determination is performed with an identification code contained in the frame (this identification code is hereinafter referred to as a header pattern). When the frame detected by the MPU 21 is the connection ID request communication frame, the MPU 21 generates a transmit frame that contains the receive status (that is a normal receive status or a receive error detection status) and the status information of the operation board 3 and transmits the transmit frame to the NC unit 1. On the other hand, when the operation board 3 receives the normal transmit frame that is free of a CRC error, the MPU 21 stores an output signal for the LED display devices 108 to the LED output storing portion 25 of the operation board 3 and sets a normal receive status. When the receive frame contains a CRC error, the MPU 21 sets the receive error detection status. Thereafter, the MPU 21 places input information of which the scan data input portion 27 has scanned the operation keys 107 of the operation board 3 into the transmit frame along with the normal receive status or the receive error detection status, and transmits the resultant frame to the NC unit 1. After the MPU 21 has completely transmitted the transmit frame, it enters the receive waiting state. When the NC unit 1 receives a frame from the operation board 3, the MPU 21 repeats the above-described operations.
Next, the operation board 3, the remote I/O 2, and the communication controlling portion of the NC unit 1 shown in FIGS. 17, 18, and 19 will be supplementally described. In the process of which the MPU 101 of the NC unit 1 transmits a frame that requests the status for the operation board 3 to the communication controlling portion for the operation board (at steps S1 and S2 of FIG. 20), data to be transmitted to the transmit data storing portion 43 is prepared beforehand. In addition to a process for writing a transmit start command to the transmit start command controlling portion 45, as a preparation for receiving a frame transmitted from the operation board 3, a receive start command is written to the receive start command controlling portion 47 beforehand.
In the outlined structure of the operation board 3 shown in FIG. 17, as the output process of which the MPU 21 of the operation board outputs data to the LED display devices 108 (at step S29 of FIG. 22), the MPU 21 stores LED output data to the LED output storing portion 25 of the operation board. In the operation key input process (at step S30 of FIG. 22), the MPU 21 sets a scan address to the scan address generating portion 26 of the operation board. The MPU 21 reads input data of the operation keys 107 from the scan data input portion 27 of the operation board.
In the above described conventional system, the communication control performed between the NC unit 1 and the operation board 3 is completely different from the communication control performed between the NC unit 1 and the remote I/O 2. The NC unit 1 is equipped with the dedicated communication controlling portion 104 and the dedicated transmit/receive signal line 112 for the operation board 3. Likewise, the NC unit 1 is equipped with the dedicated communication controlling portion 105 and the dedicated transmit/receive signal line 111 for the remote I/O 2. Thus, the NC unit 1 requires two types of serial signal lines that are dedicated, not flexible. In particular, when a machine tool is controlled, an operation board 3 is only temporarily used. In other words, when the machine tool is normally operated, it is not necessary to connect the operation board 3 thereto. Thus, such dedicated signal lines deteriorate the flexibility of the system structure.
In the conventional system, the NC unit 1 is equipped with the MPU 101. In addition, to accomplish the function of the operation board 3, the operation board 3 is equipped with MPU 21 that operates under the control of program software. Thus, the operation board 3 must have the dedicated MPU 21 and memories 23 and 24, which are necessary for the operation of the MPU 21. Consequently, the hardware cost of the operation board 3 is high.
In addition, in the conventional system, when input data from the operation keys 107 of the operation board 3 is transmitted to the NC unit 1, the MPU 21 performs a blinking control process for the LED display devices 108 to confirm the operation of the NC unit 1. To control the operation, the dedicated software must be developed. This conventional approach is both expensive and susceptible to software bug problems.
In the conventional system, code conversion table data for transmitting input data from the operation keys 107 of the operation board 3 to the NC unit 1 is stored in the memory ROM 23 of the operation board 3. When a frame is transmitted to the NC unit 1, the data is converted into a format of which the NC unit 1 can read. Each operation board 3 has code conversion table data. Thus, it is very troublesome to manage the data.
In a numerical control (NC) unit disclosed in Japanese Patent Laid-Open Publication No. 60-54012, an NC operation board and a machine operation board are selectively connected to the same interface of the NC unit. This related art reference discloses selecting the NC operation board and the machine operation board, however, no improvement is made for the NC operation board itself. In addition, no communication controlling system is defined, thus, the unit suffers from a lack of flexibility.